This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 11 |
| 3 | 247 |
| 4 | 8571 |
| 5 | 404791 |
| 6 | 24246439 |
| 7 | 1761559647 |
| 8 | 150540054611 |
| 9 | 14798051914231 |
| 10 | 1645040516034927 |
| 11 | 204068062926942655 |
| 12 | 27946847973073178587 |
| 13 | 4188043229601371413911 |
| 14 | 681707014005609312133175 |
| 15 | 119774859918869807700934111 |
| 16 | 22592863584958717501615734051 |
| 17 | 4553853548371236985017395321335 |